A surge protector is generally applied in an electric circuit and used at home, office, or factory to prevent electric equipment's from being damaged by transient overvoltage. When the electric circuit or a communication circuit produces a peak current or voltage by external interference, the surge protector is capable of conducting shunt current in a very short time to avoid electric surge from damaging other equipments in the circuit.
In general, a surge protector includes a metal oxide varistor (which is one kind of the varistors), and the varistor may be aged after a long time of use and generate heat easily. To prevent accidents such as a fire caused by the rise of temperature, the surge protector usually comes with a release mechanism connected in series with the varistor, so that when the temperature rises, the varistor is released and disconnected from the circuit. As disclosed in P.R.C. Pat. Application No. 201420368586.2, a conventional release mechanism comprises a box body, a semiconductor ceramic chip, a ceramic shielding body, and a release electrode plate. A plane of the release electrode plate is attached to one side of the semiconductor ceramic chip, and the other side of the semiconductor ceramic chip is attached to the left electrode pin. A convex side of the release electrode plate is installed into a positioning hole of the box body. The rotating hole of the ceramic shielding body is sheathed on a shaft of the box body. An edge of a soldering hole of the ceramic shielding body and the periphery of the soldering hole are covered by a solderable metal layer. The solderable metal layer is soldered with a convex side of the release electrode plate. The right electrode pin of the box body passes through the conductive wire and is soldered with the solderable metal layer. A pushrod of the spring device is installed into a slide slot. The ceramic shielding body is pushed or pulled under the effect of the elasticity of the spring. The ceramic shielding body is rotated to drive the conductive wire of the release electrode plate and the right electrode pin to move, so as to shield the electric arc. A turning block on the pushrod is used to trigger a warning switch.
However, the conventional release mechanism has the following problems: (1) The convex side of the release electrode plate is installed into the positioning hole of the box body, so that after the soldering point is disconnected, the ceramic shielding body and the release electrode plate are moved together. If the moving distance is too short, the wiring cannot be cut off completely. (2) The right electrode pin and the release electrode plate are coupled with each other by the conductive wire and the solderable metal layer, so that the connecting structure is very complicated, and occupies a large space, thus the failure rate increases.
In view of the aforementioned drawbacks of the prior art, the discloser of this disclosure conducted extensive research and provided a feasible design to overcome the drawbacks of the prior art.